Many different types of transmission lines exist and are used for a variety of purposes. For example, transmission lines are often used as the media that carries data over long distances, medium distances, and short distances. A transmission line may be anything from a coaxial cable carrying data signals over long distances to an almost microscopic metal trace that carries signals within tiny integrated circuits. As is known, a signal driven onto one end of a transmission line reflects off of the other end of the transmission line unless the other end of the transmission line is terminated with an impedance that matches the characteristic impedance of the transmission line. As is also known, driving a periodic signal onto a transmission line may cause voltage and/or current wave patterns with distinct characteristics to be induced on the transmission line. For example, a periodic signal whose frequency corresponds to a quarter wave or a half wave of the length of a transmission will typically generate a resonate standing wave on the transmission line if the transmission line is terminated in an open circuit or a short circuit.
Under certain circumstances, it may be advantageous to determine the length of, propagation delay through, or other characteristic of a transmission line. As just one (non-limiting) example, there are circumstances in which it would be advantageous to adjusts the propagation delay through a plurality of transmission lines so that signals driven through the transmission lines arrive at their destinations at the same time or within a specified tolerance. For this and other applications, it would be advantageous to utilize wave reflection properties of a transmission line to determine one or more characteristics of the transmission line.